The Topasses were one of the stranger products of European colonialism in Southeast Asia. Known as the 'Black Portuguese,' they were a mixed community of European-Asian descendants, freed slaves called Mardijkers, and local converts to Christianity -- people who spoke Portuguese, practiced Catholicism, and wielded more power on Timor than the Portuguese crown itself. When Lisbon tried to impose direct rule by installing governors, the Topasses removed them. For decades, there was simply no Portuguese governorship at all. The Topasses answered to their own leaders, chief among them the da Costa family, and they controlled the island's inland polities through a web of alliances, marriages, and coercion. By the 1740s, Gaspar da Costa commanded the most formidable military force on Timor. The VOC, clinging to its coastal fort at Kupang since 1653, watched the Topass expansion with mounting alarm.

Da Costa's army camped on the Penfui hillside and built fortifications of stone and packed earth, a chain of defensive positions stretching across the slope. The strategy was sound in principle -- approach Kupang from high ground, force the Dutch to attack uphill. But da Costa had assembled his army from unwilling partners. The Amarasi kingdom and other Timorese polities had been pressed into service; their loyalty to the Topass cause was thin. Inside Kupang, panic had already thinned the population. Civilians fled before the approaching army. The VOC's native allies from the islands of Rote and Sabu were demoralized, and it took promises from the Dutch commander -- along with the deliberate scuttling of escape vessels -- to keep them from abandoning the fight entirely. The stage was set for a battle where neither side fully trusted its own forces.

When the Dutch marched out of Kupang on that Sunday morning, the first fortification they encountered belonged to the Amarasi. What happened next was more diplomacy than combat. The Amarasi sent an envoy to the Dutch declaring that they 'could from now on be called friends of the Dutch,' then walked off the battlefield without firing a shot. The Dutch let them go. As the column advanced to the next fortification, a cascade of defections followed -- one after another, the conscripted Timorese forces abandoned da Costa. The Topasses, left increasingly alone in their stone forts, fought on. The Dutch took the positions one at a time, and as momentum shifted, their own Timorese allies finally joined the attack. Cornered in the last redoubt, da Costa tried to flee on horseback. An assegai struck him from his mount. He was beheaded. Around 2,000 died in the fighting, including many Topass officers and three native rajas. Dutch casualties were minimal -- nineteen Timorese, one Mardijker, and two volunteers.

The aftermath was brutal. Timorese allies of the Dutch beheaded the fallen, and a letter to the VOC Governor-General in Batavia reported over a thousand heads taken. Topass regalia -- objects of deep spiritual significance -- were seized as trophies. Even the Portuguese Governor of Timor showed no sympathy for the vanquished, remarking that da Costa had deserved his fate for ignoring warnings against the campaign. Over the following twelve years, polities across Timor realigned from Portuguese to Dutch allegiance. In 1769, the Portuguese shifted their headquarters from Lifau in the west to Dili in the east, conceding the western half of the island. The ensuing Dutch-Portuguese boundary, not formalized until the nineteenth century, hardened into the modern border between West Timor and East Timor -- a line that endured through the Indonesian invasion of 1975 and East Timor's independence in 2002. Today, the hillside where da Costa's army built its stone forts, where the Amarasi switched sides and the Topass empire crumbled, lies beneath the runways and terminals of El Tari International Airport.

History has a habit of erasing the people who matter most. Ensign Lipp, the officer who actually commanded the Dutch forces at Penfui, later quarreled with his superior in Kupang, and records of his role in the victory were quietly suppressed. The Mardijkers -- freed slaves who fought alongside the Dutch -- went uncredited because the VOC considered them a potential threat. Even the battle's broader significance has been debated. One Dutch historian argued that calling Penfui a turning point in Timorese history is an 'exaggeration,' yet conceded that the balance of power shifted dramatically, and had da Costa won, Timor and the Solor archipelago might have remained entirely Portuguese. In local tradition, the VOC's victory was eventually attributed to divine intervention -- even by the Topasses themselves, the very people it destroyed.